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-rw-r--r--src/pkg/strings/strings.go725
1 files changed, 0 insertions, 725 deletions
diff --git a/src/pkg/strings/strings.go b/src/pkg/strings/strings.go
deleted file mode 100644
index 5d46211d8..000000000
--- a/src/pkg/strings/strings.go
+++ /dev/null
@@ -1,725 +0,0 @@
-// Copyright 2009 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Package strings implements simple functions to manipulate strings.
-package strings
-
-import (
- "unicode"
- "unicode/utf8"
-)
-
-// explode splits s into an array of UTF-8 sequences, one per Unicode character (still strings) up to a maximum of n (n < 0 means no limit).
-// Invalid UTF-8 sequences become correct encodings of U+FFF8.
-func explode(s string, n int) []string {
- if n == 0 {
- return nil
- }
- l := utf8.RuneCountInString(s)
- if n <= 0 || n > l {
- n = l
- }
- a := make([]string, n)
- var size int
- var ch rune
- i, cur := 0, 0
- for ; i+1 < n; i++ {
- ch, size = utf8.DecodeRuneInString(s[cur:])
- if ch == utf8.RuneError {
- a[i] = string(utf8.RuneError)
- } else {
- a[i] = s[cur : cur+size]
- }
- cur += size
- }
- // add the rest, if there is any
- if cur < len(s) {
- a[i] = s[cur:]
- }
- return a
-}
-
-// primeRK is the prime base used in Rabin-Karp algorithm.
-const primeRK = 16777619
-
-// hashstr returns the hash and the appropriate multiplicative
-// factor for use in Rabin-Karp algorithm.
-func hashstr(sep string) (uint32, uint32) {
- hash := uint32(0)
- for i := 0; i < len(sep); i++ {
- hash = hash*primeRK + uint32(sep[i])
-
- }
- var pow, sq uint32 = 1, primeRK
- for i := len(sep); i > 0; i >>= 1 {
- if i&1 != 0 {
- pow *= sq
- }
- sq *= sq
- }
- return hash, pow
-}
-
-// Count counts the number of non-overlapping instances of sep in s.
-func Count(s, sep string) int {
- n := 0
- // special cases
- switch {
- case len(sep) == 0:
- return utf8.RuneCountInString(s) + 1
- case len(sep) == 1:
- // special case worth making fast
- c := sep[0]
- for i := 0; i < len(s); i++ {
- if s[i] == c {
- n++
- }
- }
- return n
- case len(sep) > len(s):
- return 0
- case len(sep) == len(s):
- if sep == s {
- return 1
- }
- return 0
- }
- hashsep, pow := hashstr(sep)
- h := uint32(0)
- for i := 0; i < len(sep); i++ {
- h = h*primeRK + uint32(s[i])
- }
- lastmatch := 0
- if h == hashsep && s[:len(sep)] == sep {
- n++
- lastmatch = len(sep)
- }
- for i := len(sep); i < len(s); {
- h *= primeRK
- h += uint32(s[i])
- h -= pow * uint32(s[i-len(sep)])
- i++
- if h == hashsep && lastmatch <= i-len(sep) && s[i-len(sep):i] == sep {
- n++
- lastmatch = i
- }
- }
- return n
-}
-
-// Contains returns true if substr is within s.
-func Contains(s, substr string) bool {
- return Index(s, substr) >= 0
-}
-
-// ContainsAny returns true if any Unicode code points in chars are within s.
-func ContainsAny(s, chars string) bool {
- return IndexAny(s, chars) >= 0
-}
-
-// ContainsRune returns true if the Unicode code point r is within s.
-func ContainsRune(s string, r rune) bool {
- return IndexRune(s, r) >= 0
-}
-
-// Index returns the index of the first instance of sep in s, or -1 if sep is not present in s.
-func Index(s, sep string) int {
- n := len(sep)
- switch {
- case n == 0:
- return 0
- case n == 1:
- return IndexByte(s, sep[0])
- case n == len(s):
- if sep == s {
- return 0
- }
- return -1
- case n > len(s):
- return -1
- }
- // Hash sep.
- hashsep, pow := hashstr(sep)
- var h uint32
- for i := 0; i < n; i++ {
- h = h*primeRK + uint32(s[i])
- }
- if h == hashsep && s[:n] == sep {
- return 0
- }
- for i := n; i < len(s); {
- h *= primeRK
- h += uint32(s[i])
- h -= pow * uint32(s[i-n])
- i++
- if h == hashsep && s[i-n:i] == sep {
- return i - n
- }
- }
- return -1
-}
-
-// LastIndex returns the index of the last instance of sep in s, or -1 if sep is not present in s.
-func LastIndex(s, sep string) int {
- n := len(sep)
- if n == 0 {
- return len(s)
- }
- c := sep[0]
- if n == 1 {
- // special case worth making fast
- for i := len(s) - 1; i >= 0; i-- {
- if s[i] == c {
- return i
- }
- }
- return -1
- }
- // n > 1
- for i := len(s) - n; i >= 0; i-- {
- if s[i] == c && s[i:i+n] == sep {
- return i
- }
- }
- return -1
-}
-
-// IndexRune returns the index of the first instance of the Unicode code point
-// r, or -1 if rune is not present in s.
-func IndexRune(s string, r rune) int {
- switch {
- case r < 0x80:
- b := byte(r)
- for i := 0; i < len(s); i++ {
- if s[i] == b {
- return i
- }
- }
- default:
- for i, c := range s {
- if c == r {
- return i
- }
- }
- }
- return -1
-}
-
-// IndexAny returns the index of the first instance of any Unicode code point
-// from chars in s, or -1 if no Unicode code point from chars is present in s.
-func IndexAny(s, chars string) int {
- if len(chars) > 0 {
- for i, c := range s {
- for _, m := range chars {
- if c == m {
- return i
- }
- }
- }
- }
- return -1
-}
-
-// LastIndexAny returns the index of the last instance of any Unicode code
-// point from chars in s, or -1 if no Unicode code point from chars is
-// present in s.
-func LastIndexAny(s, chars string) int {
- if len(chars) > 0 {
- for i := len(s); i > 0; {
- rune, size := utf8.DecodeLastRuneInString(s[0:i])
- i -= size
- for _, m := range chars {
- if rune == m {
- return i
- }
- }
- }
- }
- return -1
-}
-
-// Generic split: splits after each instance of sep,
-// including sepSave bytes of sep in the subarrays.
-func genSplit(s, sep string, sepSave, n int) []string {
- if n == 0 {
- return nil
- }
- if sep == "" {
- return explode(s, n)
- }
- if n < 0 {
- n = Count(s, sep) + 1
- }
- c := sep[0]
- start := 0
- a := make([]string, n)
- na := 0
- for i := 0; i+len(sep) <= len(s) && na+1 < n; i++ {
- if s[i] == c && (len(sep) == 1 || s[i:i+len(sep)] == sep) {
- a[na] = s[start : i+sepSave]
- na++
- start = i + len(sep)
- i += len(sep) - 1
- }
- }
- a[na] = s[start:]
- return a[0 : na+1]
-}
-
-// SplitN slices s into substrings separated by sep and returns a slice of
-// the substrings between those separators.
-// If sep is empty, SplitN splits after each UTF-8 sequence.
-// The count determines the number of substrings to return:
-// n > 0: at most n substrings; the last substring will be the unsplit remainder.
-// n == 0: the result is nil (zero substrings)
-// n < 0: all substrings
-func SplitN(s, sep string, n int) []string { return genSplit(s, sep, 0, n) }
-
-// SplitAfterN slices s into substrings after each instance of sep and
-// returns a slice of those substrings.
-// If sep is empty, SplitAfterN splits after each UTF-8 sequence.
-// The count determines the number of substrings to return:
-// n > 0: at most n substrings; the last substring will be the unsplit remainder.
-// n == 0: the result is nil (zero substrings)
-// n < 0: all substrings
-func SplitAfterN(s, sep string, n int) []string {
- return genSplit(s, sep, len(sep), n)
-}
-
-// Split slices s into all substrings separated by sep and returns a slice of
-// the substrings between those separators.
-// If sep is empty, Split splits after each UTF-8 sequence.
-// It is equivalent to SplitN with a count of -1.
-func Split(s, sep string) []string { return genSplit(s, sep, 0, -1) }
-
-// SplitAfter slices s into all substrings after each instance of sep and
-// returns a slice of those substrings.
-// If sep is empty, SplitAfter splits after each UTF-8 sequence.
-// It is equivalent to SplitAfterN with a count of -1.
-func SplitAfter(s, sep string) []string {
- return genSplit(s, sep, len(sep), -1)
-}
-
-// Fields splits the string s around each instance of one or more consecutive white space
-// characters, as defined by unicode.IsSpace, returning an array of substrings of s or an
-// empty list if s contains only white space.
-func Fields(s string) []string {
- return FieldsFunc(s, unicode.IsSpace)
-}
-
-// FieldsFunc splits the string s at each run of Unicode code points c satisfying f(c)
-// and returns an array of slices of s. If all code points in s satisfy f(c) or the
-// string is empty, an empty slice is returned.
-func FieldsFunc(s string, f func(rune) bool) []string {
- // First count the fields.
- n := 0
- inField := false
- for _, rune := range s {
- wasInField := inField
- inField = !f(rune)
- if inField && !wasInField {
- n++
- }
- }
-
- // Now create them.
- a := make([]string, n)
- na := 0
- fieldStart := -1 // Set to -1 when looking for start of field.
- for i, rune := range s {
- if f(rune) {
- if fieldStart >= 0 {
- a[na] = s[fieldStart:i]
- na++
- fieldStart = -1
- }
- } else if fieldStart == -1 {
- fieldStart = i
- }
- }
- if fieldStart >= 0 { // Last field might end at EOF.
- a[na] = s[fieldStart:]
- }
- return a
-}
-
-// Join concatenates the elements of a to create a single string. The separator string
-// sep is placed between elements in the resulting string.
-func Join(a []string, sep string) string {
- if len(a) == 0 {
- return ""
- }
- if len(a) == 1 {
- return a[0]
- }
- n := len(sep) * (len(a) - 1)
- for i := 0; i < len(a); i++ {
- n += len(a[i])
- }
-
- b := make([]byte, n)
- bp := copy(b, a[0])
- for _, s := range a[1:] {
- bp += copy(b[bp:], sep)
- bp += copy(b[bp:], s)
- }
- return string(b)
-}
-
-// HasPrefix tests whether the string s begins with prefix.
-func HasPrefix(s, prefix string) bool {
- return len(s) >= len(prefix) && s[0:len(prefix)] == prefix
-}
-
-// HasSuffix tests whether the string s ends with suffix.
-func HasSuffix(s, suffix string) bool {
- return len(s) >= len(suffix) && s[len(s)-len(suffix):] == suffix
-}
-
-// Map returns a copy of the string s with all its characters modified
-// according to the mapping function. If mapping returns a negative value, the character is
-// dropped from the string with no replacement.
-func Map(mapping func(rune) rune, s string) string {
- // In the worst case, the string can grow when mapped, making
- // things unpleasant. But it's so rare we barge in assuming it's
- // fine. It could also shrink but that falls out naturally.
- maxbytes := len(s) // length of b
- nbytes := 0 // number of bytes encoded in b
- // The output buffer b is initialized on demand, the first
- // time a character differs.
- var b []byte
-
- for i, c := range s {
- r := mapping(c)
- if b == nil {
- if r == c {
- continue
- }
- b = make([]byte, maxbytes)
- nbytes = copy(b, s[:i])
- }
- if r >= 0 {
- wid := 1
- if r >= utf8.RuneSelf {
- wid = utf8.RuneLen(r)
- }
- if nbytes+wid > maxbytes {
- // Grow the buffer.
- maxbytes = maxbytes*2 + utf8.UTFMax
- nb := make([]byte, maxbytes)
- copy(nb, b[0:nbytes])
- b = nb
- }
- nbytes += utf8.EncodeRune(b[nbytes:maxbytes], r)
- }
- }
- if b == nil {
- return s
- }
- return string(b[0:nbytes])
-}
-
-// Repeat returns a new string consisting of count copies of the string s.
-func Repeat(s string, count int) string {
- b := make([]byte, len(s)*count)
- bp := 0
- for i := 0; i < count; i++ {
- bp += copy(b[bp:], s)
- }
- return string(b)
-}
-
-// ToUpper returns a copy of the string s with all Unicode letters mapped to their upper case.
-func ToUpper(s string) string { return Map(unicode.ToUpper, s) }
-
-// ToLower returns a copy of the string s with all Unicode letters mapped to their lower case.
-func ToLower(s string) string { return Map(unicode.ToLower, s) }
-
-// ToTitle returns a copy of the string s with all Unicode letters mapped to their title case.
-func ToTitle(s string) string { return Map(unicode.ToTitle, s) }
-
-// ToUpperSpecial returns a copy of the string s with all Unicode letters mapped to their
-// upper case, giving priority to the special casing rules.
-func ToUpperSpecial(_case unicode.SpecialCase, s string) string {
- return Map(func(r rune) rune { return _case.ToUpper(r) }, s)
-}
-
-// ToLowerSpecial returns a copy of the string s with all Unicode letters mapped to their
-// lower case, giving priority to the special casing rules.
-func ToLowerSpecial(_case unicode.SpecialCase, s string) string {
- return Map(func(r rune) rune { return _case.ToLower(r) }, s)
-}
-
-// ToTitleSpecial returns a copy of the string s with all Unicode letters mapped to their
-// title case, giving priority to the special casing rules.
-func ToTitleSpecial(_case unicode.SpecialCase, s string) string {
- return Map(func(r rune) rune { return _case.ToTitle(r) }, s)
-}
-
-// isSeparator reports whether the rune could mark a word boundary.
-// TODO: update when package unicode captures more of the properties.
-func isSeparator(r rune) bool {
- // ASCII alphanumerics and underscore are not separators
- if r <= 0x7F {
- switch {
- case '0' <= r && r <= '9':
- return false
- case 'a' <= r && r <= 'z':
- return false
- case 'A' <= r && r <= 'Z':
- return false
- case r == '_':
- return false
- }
- return true
- }
- // Letters and digits are not separators
- if unicode.IsLetter(r) || unicode.IsDigit(r) {
- return false
- }
- // Otherwise, all we can do for now is treat spaces as separators.
- return unicode.IsSpace(r)
-}
-
-// Title returns a copy of the string s with all Unicode letters that begin words
-// mapped to their title case.
-//
-// BUG: The rule Title uses for word boundaries does not handle Unicode punctuation properly.
-func Title(s string) string {
- // Use a closure here to remember state.
- // Hackish but effective. Depends on Map scanning in order and calling
- // the closure once per rune.
- prev := ' '
- return Map(
- func(r rune) rune {
- if isSeparator(prev) {
- prev = r
- return unicode.ToTitle(r)
- }
- prev = r
- return r
- },
- s)
-}
-
-// TrimLeftFunc returns a slice of the string s with all leading
-// Unicode code points c satisfying f(c) removed.
-func TrimLeftFunc(s string, f func(rune) bool) string {
- i := indexFunc(s, f, false)
- if i == -1 {
- return ""
- }
- return s[i:]
-}
-
-// TrimRightFunc returns a slice of the string s with all trailing
-// Unicode code points c satisfying f(c) removed.
-func TrimRightFunc(s string, f func(rune) bool) string {
- i := lastIndexFunc(s, f, false)
- if i >= 0 && s[i] >= utf8.RuneSelf {
- _, wid := utf8.DecodeRuneInString(s[i:])
- i += wid
- } else {
- i++
- }
- return s[0:i]
-}
-
-// TrimFunc returns a slice of the string s with all leading
-// and trailing Unicode code points c satisfying f(c) removed.
-func TrimFunc(s string, f func(rune) bool) string {
- return TrimRightFunc(TrimLeftFunc(s, f), f)
-}
-
-// IndexFunc returns the index into s of the first Unicode
-// code point satisfying f(c), or -1 if none do.
-func IndexFunc(s string, f func(rune) bool) int {
- return indexFunc(s, f, true)
-}
-
-// LastIndexFunc returns the index into s of the last
-// Unicode code point satisfying f(c), or -1 if none do.
-func LastIndexFunc(s string, f func(rune) bool) int {
- return lastIndexFunc(s, f, true)
-}
-
-// indexFunc is the same as IndexFunc except that if
-// truth==false, the sense of the predicate function is
-// inverted.
-func indexFunc(s string, f func(rune) bool, truth bool) int {
- start := 0
- for start < len(s) {
- wid := 1
- r := rune(s[start])
- if r >= utf8.RuneSelf {
- r, wid = utf8.DecodeRuneInString(s[start:])
- }
- if f(r) == truth {
- return start
- }
- start += wid
- }
- return -1
-}
-
-// lastIndexFunc is the same as LastIndexFunc except that if
-// truth==false, the sense of the predicate function is
-// inverted.
-func lastIndexFunc(s string, f func(rune) bool, truth bool) int {
- for i := len(s); i > 0; {
- r, size := utf8.DecodeLastRuneInString(s[0:i])
- i -= size
- if f(r) == truth {
- return i
- }
- }
- return -1
-}
-
-func makeCutsetFunc(cutset string) func(rune) bool {
- return func(r rune) bool { return IndexRune(cutset, r) >= 0 }
-}
-
-// Trim returns a slice of the string s with all leading and
-// trailing Unicode code points contained in cutset removed.
-func Trim(s string, cutset string) string {
- if s == "" || cutset == "" {
- return s
- }
- return TrimFunc(s, makeCutsetFunc(cutset))
-}
-
-// TrimLeft returns a slice of the string s with all leading
-// Unicode code points contained in cutset removed.
-func TrimLeft(s string, cutset string) string {
- if s == "" || cutset == "" {
- return s
- }
- return TrimLeftFunc(s, makeCutsetFunc(cutset))
-}
-
-// TrimRight returns a slice of the string s, with all trailing
-// Unicode code points contained in cutset removed.
-func TrimRight(s string, cutset string) string {
- if s == "" || cutset == "" {
- return s
- }
- return TrimRightFunc(s, makeCutsetFunc(cutset))
-}
-
-// TrimSpace returns a slice of the string s, with all leading
-// and trailing white space removed, as defined by Unicode.
-func TrimSpace(s string) string {
- return TrimFunc(s, unicode.IsSpace)
-}
-
-// TrimPrefix returns s without the provided leading prefix string.
-// If s doesn't start with prefix, s is returned unchanged.
-func TrimPrefix(s, prefix string) string {
- if HasPrefix(s, prefix) {
- return s[len(prefix):]
- }
- return s
-}
-
-// TrimSuffix returns s without the provided trailing suffix string.
-// If s doesn't end with suffix, s is returned unchanged.
-func TrimSuffix(s, suffix string) string {
- if HasSuffix(s, suffix) {
- return s[:len(s)-len(suffix)]
- }
- return s
-}
-
-// Replace returns a copy of the string s with the first n
-// non-overlapping instances of old replaced by new.
-// If n < 0, there is no limit on the number of replacements.
-func Replace(s, old, new string, n int) string {
- if old == new || n == 0 {
- return s // avoid allocation
- }
-
- // Compute number of replacements.
- if m := Count(s, old); m == 0 {
- return s // avoid allocation
- } else if n < 0 || m < n {
- n = m
- }
-
- // Apply replacements to buffer.
- t := make([]byte, len(s)+n*(len(new)-len(old)))
- w := 0
- start := 0
- for i := 0; i < n; i++ {
- j := start
- if len(old) == 0 {
- if i > 0 {
- _, wid := utf8.DecodeRuneInString(s[start:])
- j += wid
- }
- } else {
- j += Index(s[start:], old)
- }
- w += copy(t[w:], s[start:j])
- w += copy(t[w:], new)
- start = j + len(old)
- }
- w += copy(t[w:], s[start:])
- return string(t[0:w])
-}
-
-// EqualFold reports whether s and t, interpreted as UTF-8 strings,
-// are equal under Unicode case-folding.
-func EqualFold(s, t string) bool {
- for s != "" && t != "" {
- // Extract first rune from each string.
- var sr, tr rune
- if s[0] < utf8.RuneSelf {
- sr, s = rune(s[0]), s[1:]
- } else {
- r, size := utf8.DecodeRuneInString(s)
- sr, s = r, s[size:]
- }
- if t[0] < utf8.RuneSelf {
- tr, t = rune(t[0]), t[1:]
- } else {
- r, size := utf8.DecodeRuneInString(t)
- tr, t = r, t[size:]
- }
-
- // If they match, keep going; if not, return false.
-
- // Easy case.
- if tr == sr {
- continue
- }
-
- // Make sr < tr to simplify what follows.
- if tr < sr {
- tr, sr = sr, tr
- }
- // Fast check for ASCII.
- if tr < utf8.RuneSelf && 'A' <= sr && sr <= 'Z' {
- // ASCII, and sr is upper case. tr must be lower case.
- if tr == sr+'a'-'A' {
- continue
- }
- return false
- }
-
- // General case. SimpleFold(x) returns the next equivalent rune > x
- // or wraps around to smaller values.
- r := unicode.SimpleFold(sr)
- for r != sr && r < tr {
- r = unicode.SimpleFold(r)
- }
- if r == tr {
- continue
- }
- return false
- }
-
- // One string is empty. Are both?
- return s == t
-}
generated by cgit v1.2.3 (git 2.39.1) at 2025-04-30 04:38:16 +0000